The present invention utilizes a conductive material that provides overvoltage protection upon a printed circuit board. Conductive material providing overvoltage protection is set forth in U.S. application Ser. No. 08/317,988 (recently allowed); U.S. Pat. Nos. 5,248,517; 4,977,357; 5,068,634; 5,099,380; 5,142,263; 5,189,387; 5,260,848; 5,262,754; and 5,248,517 which are incorporated by reference.
These patents relate to the conductive material composition, applications of the conductive material to electrical components, such as POLYCLAMP.RTM. connectors by AMP Incorporated (part numbers 93711-1 to 93716-1). In particular, the conductive material referred to mostly in the patents is an aluminum filled silicone rubber. This conductive material has for example the composition of 28.8 wt % silicone rubber, Q4475-8 by Dow Corning; 52.4 wt % aluminum powder, x30 (spherical) by Alcan; 15.7 wt % aluminum trihydrate, hydral 705; and 3.1 wt % organic peroxide curing agent, CST peroxide. This conductive material is a rubbery composition which makes it extremely difficult to uniformly apply the material to non-planar objects that require a uniform application, like printed circuit boards. In some instances, the conductive material is applied into holes of a perforated conductor to allow the rubbery puddy conductive material to be applied easier. Moreover, overlaying the conductive material or perforated conductor is a full metal electrode, such as a foil material that is soldered or plated to ground contacts.
It has been suggested in U.S. Pat. No. 5,248,517 to make the conductive material paintable/coatable. To make the conductive material paintable/coatable, the material is combined with a solvent such as naphtha, xylene, acetone or methyl-ethyl ketone. After the conductive material is applied to the desired electronic component, the solvent of the conductive material evaporates during a curing process at 120.degree. C. The conductive material has even been contemplated to be applied to printed circuit boards.
The function of the inventions disclosed in these patents has also been to filter out electrostatic spikes and to protect electronic components from damage. These patents however have limited the application of these patents to the puddy-like and paintable conductive material composition and applying this conductive material to electronic components, specifically connectors or printed circuit boards.